Source reduction
Using less material in the first place, the top of the waste hierarchy.
Source reduction means not producing the material at all: fewer pallets, lighter pallets, or pallets used for more trips. In EPA's WARM model it is a separate pathway with its own factor.
For dimensional lumber, WARM's source reduction factor with the current mix of inputs is −2.11 MTCO2E per short ton (Exhibit 12-3), larger than the reuse credit of −1.66. Not making a pallet avoids its manufacturing emissions and leaves its wood in the forest.
For a site, source reduction looks like switching suppliers to pooled pallets, asking for fewer pallets per load, or reusing inbound pallets for outbound freight instead of buying new. The Pallet Fate Report models end of life, not source reduction, so report reduction separately.
It's the one option that needs no outlet at all.
Sources
- Documentation for Greenhouse Gas Emission and Energy Factors Used in WARM, Version 16: Construction Materials Chapters, ch. 12 Wood Products (EPA-530-R-23-020) U.S. EPA. Accessed October 27, 2026. Exhibits 12-3 (p. 12-3), 12-9, 12-13, 12-15 and 12-16 (p. 12-10).